The present application is based on Japanese Patent Applications No. 2011-201491 filed on Sep. 15, 2011, the entire contents of which are hereby incorporated by reference.
1. Technical Field
The present invention relates to a method for manufacturing a nitride semiconductor substrate for manufacturing a plurality of nitride semiconductor substrates from a nitride semiconductor single crystal.
2. Description of Related Art
In order to fabricate a compound semiconductor substrate, there is a method of growing a compound semiconductor crystal (ingot) by a liquid-phase growth or a vapor-phase growth, then slicing an obtained ingot, to thereby fabricate a substrate (wafer).
In a fabrication technique of the compound semiconductor substrate, for example, outer cylindrical grinding for grinding an outer periphery of the ingot is carried out, to remove impurities, etc., that exist on a skin of GaAs single crystal ingot before a wafer is fabricated by slicing the ingot of the GaAs single crystal which is crystal-grown by LEC method (a liquid encapsulating Czochralski method) (for example, see patent document 1).
Further, there is also proposed a method of making a running direction of a wire row inclined to {1-100} plane (M plane) being a cleavage plane which is most easily cleaved, for reducing the generation of a crack when the GaN ingot obtained by vapor phase epitaxy is ground (sliced) using the wire row (for example, see patent document 2).